The update allows players to add checkpoints to existing levels (or create new ones that include them). You’ll also be able to create status-dependent power-ups. For instance, a fire flower block can be set to eject a super mushroom if Mario is small.

— Mike Futter, GamerInformer

This is just a testament to how much Nintendo is working to embrace new technologies and commit to it's titles after launch. They're even adding in Nintendo curated levels and creators, including some of the levels we've only read articles about from public events.

I always got frustrated with long courses and hesitated in creating long levels due to lack of checkpoints. But that coupled with blocks that react to the state of the player makes for huge new possibilities for Mario Marker.